The sexual cycle of mares lasts an average of 19 to 22 days, with variations from 18 to 24 days. In mares with well-expressed external signs of estrus, it is noticed that they are restless, they are ticklish when brushing and during work they are often disobedient, often wet, raise their tails, there is a flash of the pubic area. The goal of a clinical examination is to establish an accurate diagnosis, on the basis of which an accurate and reliable prognosis is made. After insemination, if pregnancy occurs, we must pay special attention to the mare. During pregnancy, mares experience a number of different pathological conditions, which are of different origins and which can endanger the fetus. Injuries that occur during childbirth are also included in the pathology of childbirth, and are most often discovered only after its completion. The duration of pregnancy is genetically inherited and biologically variable, and in mares it is 336 (322 – 387) days. Fertilized eggs are 48±12 hours after ovulation in the development phase of a total of 4 or 8 cells. Pregnancy diagnosis methods are divided into breeding, clinical and laboratory methods. Four to six weeks before the foaling date, the mare should be moved to a dry, clean and warm area intended for foaling. A fetus that reaches a certain degree of maturity with its endocrine system of fetoplacental connection causes birth. In mares, the stage of pushing out the fetus is very short and ends in a few minutes (5-30 minutes). If the placenta has not come out within 2-3 hours after delivery, the treatment of retained placenta should be started. In terms of feeding young foals, it should be emphasized that the best milk for a young foal is its own mother's milk, which also protects it, establishing a mutually close relationship. Since the foal's immune system is sensitive, especially before the development of active immunity, the hygiene of the facility and the environment should be impeccable. Feeding the foals starts after two to three weeks of life, by putting quality fodder on the feeding table. It is important to wean the foal as soon as possible. The most important thing is that before the foal is weaned, it starts consuming voluminous and concentrated fodder that meets its needs for nutrients. In this period, the foal switches from liquid food (mare's milk) to herbivory, which meets its nutritional needs from concentrated and voluminous fodder. The dynamics of change and development in the foal's digestive system are great. It is essential to monitor the foal's needs for nutrients, in order to obtain a healthy, physically and mentally stable adult head capable of further breeding and work. It is recommended to keep them free in the pasture, if possible, since young horses have conditions for free movement there. Pasture and grazing should be well planned, because excessive grazing must be avoided, well maintained, and weed control implemented. This includes, for example, collecting faeces, rotating grazing, moving horses in case of heavy rains, which will muddy the pasture, to prevent health problems.